Iraqi Sunni fighters secure the funeral of a man who was killed in artillery fire in Fallujah, western Iraq, on Jan. 4, 2014. / Mohammed Jalil, epa

by Jim Michaels, USA TODAY

by Jim Michaels, USA TODAY

Al-Qaeda militants have seized Fallujah, a key city in western Iraq, engaging Iraqi army forces in pitched battles there in a brazen challenge to Iraq's central government.

"The whole of Fallujah is taken," said Qasim Abed, a member of the provincial council in the region and the former governor of Anbar. "The situation is very bad."

Abed was reached Saturday by phone from his home in Ramadi, the capital of Anbar, a mostly Sunni region west of Baghdad. He said militants have occupied police stations and government buildings throughout Fallujah and are also controlling limited parts of Ramadi.

Later Saturday, police had positioned themselves on the edge of Fallujah, head of the Anbar province police force Hadi Razeij said while speaking on Arabic language satellite broadcaster al-Arabiya.

"The walls of the city are in the hands of the police force, but the people of Fallujah are the prisoners of ISIL," he said, referring to the al-Qaeda linked Islamic State in Iraq and Levant.

Reports from the region are sketchy, and it is unlikely militants can hold any ground they have seized, analysts say.

However, the battlefield successes do provide al-Qaeda with an important propaganda victory; the militants depend on an image of invincibility for recruitment and fundraising. During the Iraq War, al-Qaeda frequently disseminated video of militants waving flags in public places.

Abed said it could take a week for government forces - and tribes who are fighting with the government - to push al-Qaeda out of the two cities. Abed said most Anbar tribes are fighting alongside government forces, but a handful have sided with the militants.

Al-Qaeda militants, emboldened by their powerful role in attempting to topple the government in neighboring Syria, have been exploiting the sense of alienation among Sunnis.

"It's a perfect storm that's been brewing for a long time," said Ryan Crocker, a former U.S. ambassador to Iraq.

The fighting in Anbar province comes amid growing sectarian tensions between the minority Sunnis and the Shiite-dominated government.

Sunnis have accused the Shiite-led government of Nouri al-Maliki of being heavy-handed in his treatment of political rivals and have responded with spasms of violence.

"Maliki has taken a very serious and unfortunate step toward pushing a large percentage of the Sunni population to feel disenfranchised," said James Jeffrey, a former U.S. ambassador to Iraq now at the Washington Institute for Near East Policy.

Recently, government forces arrested a prominent Sunni, touching off a firefight that killed the lawmaker's brother and some of his bodyguards. Security forces then dismantled a Sunni protest camp in Ramadi.

Responding to Sunni concerns, the central government agreed to withdraw its forces from Anbar cities this week. But once the forces left, al-Qaeda militants surfaced in Ramadi and Fallujah.

The fighting, the worst violence since U.S. forces left Iraq at the end of 2011, erupted just as a number of tribal leaders in recent weeks have been trying to work out a political compromise with al-Maliki's government.

"They were about to get a negotiated settlement," said Sterling Jensen, an analyst at the National Defense University's Near East South Asia Center for Strategic Studies. "For some reason, Maliki chose this time to go against the protesters."

Anbar has played an influential role in shaping Iraq's history.

After the U.S.-led invasion of Iraq in 2003, the region became a hotbed of the Sunni insurgency that fought American forces. In 2004, Fallujah had become a symbol of resistance to the U.S. presence until an American-led offensive drove militants from the city in bloody street fighting.

In 2006 and 2007, a network of tribal leaders in Ramadi who were backed by American forces led an effective revolt against al-Qaeda, helping to turn the tide of war in Iraq.

Today, tribal leaders in Anbar remain wary of al-Qaeda and have urged local police to fight the militants, analysts say.

However, they point out that it was the presence of Americans who gave tribal leaders the confidence to turn on al-Qaeda in 2006 and 2007. Sunni tribal leaders saw Americans as an ally that could protect them from al-Qaeda and the excesses of a Shiite-dominated government.

Analysts fear that Sunnis now may be driven into the arms of al-Qaeda if they feel it is the only bulwark against a government hostile to their interests.

"It's possible they are now opening their communities to an al-Qaeda they didn't like," said Stephen Biddle, a national security analyst and professor at George Washington University.

Al-Qaeda has also been strengthened by the civil war in neighboring Syria. The war there has attracted foreigners who came to fight under the al-Qaeda banner. Some of those fighters may be spilling into western Iraq, analysts say.

The fighting in Syria has given al-Qaeda in Syria "a new lease on life," Jeffrey said.

"There are no peacekeepers here to stabilize this," Biddle said. "As a result you get a very dangerous tinderbox."